The autothermal reforming of methane to syngas has been carried out in a reactor charged with both a Ni(15 wt%)-Ru (1 wt%)/Al2O3-MgO metallic monolith catalyst and an electrically-heated convertor (EHC). The standalone type reactor has a start-up time of less than 2 min with the reactant gas of 700 ℃ fed to the autothermal reactor. The O2/CH4 and H2O/CH4 ratio governed the methane conversion and temperature profile of reactor. The reactor temperature increased as the reaction shifted from endothermic to exothermic reaction with decreasing H2O/CH4 ratio. Also the amount of CO2 in the products increases with increasing H2O/CH4 ratio due to water gas shift reaction. The 97% of CH4 conversion was obtained and the reactor temperature was maintained 600 ℃ at the condition of GHSV=10,000 h^(-1) and feed ratio (H2O/CH4=0.6 and O2/CH4=0.5). In this condition, the maximum flow rate of the syngas generated from the reactor charged with 170 cc of the metallic monolith catalyst is 0.94 Nm3/h.